Circuit controller



June 3, 1941 H. L. BONE ETAL CIRCUIT CONTROLLER Filed April 13, 1939 2Sheets-Sheet l June 3, 1941. H, BONE ETAL 2,244,326 I cIRcUIT CONTROLLERFiled April 13, 1939 2 sheets-sheet 2 Fig. .5.

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lNvENToRS Herben .one, M'll'am ,.Smlfh and Q0 A. 11700019.

THEIR ATTORNE Patented June 3, 1941 UNITED STATES PATENT OFFICE CIRCUITCONTROLLER Pennsylvania Application April 13, 1939, Serial No. 267,684

Claims.

Our invention relates to circuit controllers, and particularly tomanually operable circuit controllers adapted to be assembled on acontrol panel as one of a group of similar units for controlling railwaytraflc controlling devices such as railway track switches or signals.

Circuit controllers embodying our invention are particularly welladapted for, but not limited thereto, use in railway traflc controllingsystems such as, for example, the system disclosed and claimed in theapplication for Letters Patent, Serial No. 118,609, iiled on December31, 1936, by John M. Pelikan for Railway trailic controlling apparatus.Railway traffic controlling systems of the type disclosed in theaforesaid application Serial No. 118,609 have as an integral partthereof a control panel containing a diagram of the track layout andprovided with a plurality of circuit controllers manually operable totwo extreme positions and biased to an intermediate position, forcontrolling railway trafllc controlling devices such as switches andsignals. In systems of the type described, it has been found necessaryto mount a large number of these controllers on a panel suflcientlysmall so as to enable the operator to see and operate each controllerwithout shifting his position. It has also been found necessary thatcertain of the controllers be provided with means for indicating whenthe function which is to be effected by the controller is completed. Itis readily apparent, therefore, that each controller and its associatedindicator should occupy the least possible space, thereby permittingcloser spacing of the controllers themselves and of the tracks shown inthe track layout. Furthermore, it has been found necessary that eachcontroller and associated indicator be readily accessible for repairsand replacements, thus requiring a unitary construction of thecontroller and indicator, whereby the unit as a whole is secured to thecontrol panel but is readily removable therefrom with a minimumexpenditure of time.

Accordingly, an object of our invention is the provision of novel andimproved three-position circuit controllers which are manually operableto two extreme positions wherein in each position control contacts areselectively closed or opened, and which are biased to a positionintermediate the two extreme positions.

Another object of our invention is the provision, in circuit controllersof the type described, of means for providing an indicator integral withsuch controller, in a manner such that the combination of the controllerand its associated indicator requires no more panel space than isusually required for a three-position circuit controller of usualconstruction.

A further object of our invention is the provision, in a circuitcontroller of the type described provided with an indicator, of noveland improved means for detachably securing the circuit controller andits associated indicator to the control panel, thereby permitting thedetachment of a controller and its associated indicator from the controlpanel as a unit, and permitting the attachment of that unit for anotherunit of the same type, with the control panel.

Other objects and advantages of our invention will appear as thespecication progresses.

Specically, our invention relates to improvements in circuit controllersof the type described and claimed in an application for Letters Patent,Serial No. 123,014, filed January 29, 1937, by William E. Smith.

We shall describe two forms of circuit controllers embodying ourinvention, and shall then point out the novel features thereof inclaims.

In the accompanying drawings, Fig. 1 is a top plan view showing one formof circuit controller embodying our invention. Fig. 2 is a verticalelevational view of the circuit controller shown in Fig. 1. Figs. 3 and4 are each sectional views taken substantially on the lines 3 3 and 4-4,respectively, of Fig. l. Fig. 5 is a top plan View, partially sectional,showing a modied form of the circuit controller shown in Fig. 1, andwhich modified form also embodies our invention. Fig. 6 is a. verticalelevation view of the circuit controller shown in Fig. 5. Fig. 7 is avertical elevation view showing a contact stack arrangement adapted foruse with the circuit controller shown in Fig. 5.

Similar reference characters refer to similar parts in each of theseveral views.

Referring rst to Figs. 1, 2 and 3, the reference character 8 designatesa base member provided at its forward end with an upturned leg 9 havingan opening III, and provided on its rearward end with a spring memberII. A bearing member I2 is secured to the upturned leg 9 of member 8,and is provided with a bearing boss extending through the opening I0 inthe leg 9. Slidably mounted in the bearing member I2 for longitudinalsliding movement is a tubular operating member I3, the outer end ofwhich is formed with an integral button I4 adapted to be grasped formanually operating the member, and the inner end of which is threadedinto a split collar I5 forming a part of a moulded cam member I formedof insulating material. The spiit collar I5 is provided with twolaterally extending lugs which when drawn together by a screw I?threaded therein locks operating member I3 to collar I5. The operatingmember I3 normally occupies the position shown in the drawings, but isadapted to be at times pushed inwardly from its normal position to oneextreme position and at other times to be pulled outwardly from itsnormal position to another extreme position. The operation of member I3to its eXtreme positions is adapted to selectively govern the openingand closing of control contacts provided for the circuit controller, ina manner to be described presently.

rEhe control contacts are provided for the circuit controller in aplurality of groups or stacks of contacts. here shown comprising twostacks in number, and designated by the reference characters Si and S2.These stacks are both secured to an insulating member I3 which in turnis secured by rivets i9 to the base member 8, and are each provided withtwo rows of contacts (shown in part in Figs. 2 and 3), which aresubstantially similar in construction so that only the upper or top rowof contacts of each stack is visible in Fig. l. Furthermore, both stacksare constructed substantially similar to each other, so that thefollowing description of the upper row of contacts of stack SI willsuffice not only for the lower row oi contacts of that stack, but willsuffice also to describe both the upper and lower rows of contacts ofstack S2. Referring now to fig l wherein the upper row of contacts ofstack .T SI may be best seen, this row comprises a plurality ofsuperposed biocks to, Ib and E86, formed of insulating material andattached to member I3 by means of screws 2S. A iirst movable Contactmember 2l is clamped between block 3a and member I3, and is provided onits outer end with an inwardly projecting return bend, the function ofwhich will be made clear presently. A first iixed contact finger 23 isclamped between the blocks i3d and Ib, and is retained in its normalposition by a relatively stiff metallic stop 24 which is also clampedbetween the two blocks lilo and Ih. The Contact 1Iingers ZI and 23 areso adjusted that when no outward thrust is exerted upon movable ringer 2I, the parts will occupy the positions shown, in which position movablecontact ringer 2! is out of engagement with its associated fiXed contactfinger 23. The upper row of contacts of stack SI also is provided with asecond aed Contact finger 25a clamped between insulating block Isc andmember I8, and which finger constantly engages a projection provided ona contact member 32 carried by the cam member l. The screws 2@ areinsulated from the various iingcrs and strips by means of insulatedbushings which surround the screws. As was pointed out heretofore, theconstruction of each row of contact fingers of the stacks SI and S2 issubstantially similar to the construction just described for upper rowof contact iingers of stack SI, so lthat the lower row of Contactfingers of stack SI and the upper and lower rows of contact nns ofstack. S2 will be provided each with a gagement with its associatedfixed contact finger.`

Furthermore, each row of contacts of stack SI is provided with a second:[iXed Contact finger which assises being ad pted in the normal andeXtreme inward positions of the operating member I3, to exert an outwardforce on the return bends of the movable contact fingers of Contactstack S2, thereby operating those movable contact members intoengagement with the associated fixed contact iingers. The other camsurface EI, provided on the cam i5, is adapted to exert an outward forceon the return bends of the movable contact iingers of` contact stack SI,only in the eXtreme inward position ci the operating member, therebyoperating the movable contact fingers of Contact stack Si (as forexample contact nger 2i) into engagement with the associated fixedcontact fingers (contact finger 2i engaging its associated contactfinger in this position of the member I3). From the foregoing, it isobvious that when operating member I3 is in its extreme outwardposition, thc contacts of each stack controlled thereby are open; whenoperating member E3 is in its normal position, the contacts of one stackSI are open and the contacts of the other stack S2 arc closed; and whenoperating member I3 is in its extreme inward position, the contacts ofeach stack are closed. it follows, therefore, that cam member iselectively opens or closes the control contacts provided for thecircuit controller in accordance with the position of operating memberi3. It is to be understood, of course, that the specific contact stackarrangement may be varied to best suit the contact engagement requiredfor each speciiic application of the circuit controller.

As was pointed out heretofore, cam member i is also provided withcontact members such as contact members 32 and 33 shown in Fig. l, whichengage. at all positions of the operating member I3, the respectivesecond fixed contact fingers provided for the rows of contacts of stacksSi S2. The functions of the contacts constantly formed by the engagementoi the Contact fingers provided for member I5 with the second fixedcontact ingers oi stacks SI and S2 will presently be made clear.

The operating member IE and the cam member Iii are each provided withmeans cooperating with each other for displaying an indication. As hereshown, member I3 is provided with a glass rod lightly frosted on itsextreme outer end, and extending through the operating member from onethereof to the other. The rod 35 is adapted to be illuminated at timesby light rays from one or the other of a pair of indication lamps and 3lcontained within partitioned recesses 3E and formed in cam member E5.The recesses 3E and 35i formed in member I6 are open at either end, thefront end of each recess communicating with a common chamber dcontaining the inner end of the glass rod 35. The top and the other endIof the recesses are enclosed by a suitable plate ii formed with a legportieri @-2. the main portion of plate II covering the top the recessesand being provided with suitable openings for ventilation thereof, whilethe lesr portion it closes the other or rear endof the recesses and isprovided with an opening for each recess, into each opening of which a.bayonet type lamp socket is soldered. Electrical contact is establishedwith the indication lamps, when such lamps are inserted in the abovementioned sockets, by means ofl the previously mentioned contact membersprovided for the cam member I6, and the secondfixed contact fingersprovided for contact stacks SI and S2, one contact formed thereby beinginterposed in the circuit for one lamp socket, another contact formedthereby being interposed in the circuit for the other lamp socket, andthe other contact formed thereby being interposed in the commonconnection of both sockets. Since the control circuits for lamps 36 and31 of the indication means form no part of the present invention, thecircuits for the control thereof are omitted from the drawings for thesake of clearness.

In order to permit each lamp 36 or 31 to display a distinctiveindication, the lamps may be provided with distinctively coloredenvelopes, or may be provided with clear glass envelopes and each beprovided with a distinctively colored filter. As shown, the lamps 36 and31 have clear glass envelopes and are provided with distinctivelycolored fllters 43 and 44, one lter 43 being disposed in recess 38, andthe other filter 44 being disposed in recess 39. These filters arepreferably colored one green and one red, in accordance with the usualpractice in the railway signaling art. It should be pointed out thatwhen one lamp or the other of the pair of indication lamps is controlledto its illuminated condition, the glass rod 35 traversing the operatingmember I3 becomes illuminated to display at its frosted outer end thecolored indication determined by the color filter of the indication lampthen illuminated.

'I'he leg 42 of cover plate 4| provided for the indication recesses 38and 39 formed in the cam member I6, is provided with a laterallyprojecting extension 45, which is provided with an opening 46 having alarger diameter at one end thereof than at the other. The largerdiametered portion of the opening 46 is adapted to receive the head of apin 41 moulded integrally in the member I6, and the smaller diameteredportion of the opening 46 is adapted to receive the shank of pin 41.When the cover member 4| is rst positioned so that the head of pin 41enters the larger diametered portion of opening 46, and the member isthen moved so that the smaller diametered portion receives the shankportion of the pin, the head of pin 41 then engages the extension ofmember 4| to hold that member in its normal position wherein therecesses provided in member I6 are enclosed. It is readily apparent thatby sliding cover member 4I so that the head of pin 41 can pass throughthe opening 46 in extension 45, the member 4| may then be removed fromits normal position and may be raised to a position wherein the lamps 36and 31 are accessible for inspection and replacement.

The base portion of the moulded cam member I6 is adapted to be engagedby L-shaped guide members 48 (see Fig. 4) secured to the base member 8,and which members serve to guide the sliding movement of member I6 inresponse to the operation of the operating member I3, in alignment withthe axis of the operating member.

These guiding members 48, which are secured to the base member 8 bymeans of the screws 49, by guiding the movement of the member I8 `insurecorrect operation of the contact members of the contact stacks SI andS2, and prevent any tendency of member I8 to bind, which tendency mightresult if member I6 moves out of alignment with the axis of operatingmember I3.

Moulded integrally on each lateral side of cam member I6 is a V-shapedcam surface, the function of which will be pointed out presently.

The circuit controller and indicator are adapted to be assembled as aunit on a bracket member 50, which member is provided at its forward endwith an opening 5I through which the outer end of operating member I3may pass, and which opening serves to receive the boss provided onbearing member I2 of base member 8. The bracket is further provided onits rearward end with a slot 52, which communicates with a hole 53having a predetermined diameter. The slot 52 and the hole 53 provided inbracket 50 cooperate with means on base member 8 for detachably securingthe circuit control unit to the bracket. As here shown, the base member8 is provided with an opening 54 through which the shank 21 of a largeheaded locking pin 55 operates. The pin 55, which is secured to springmember II fastened to base member 8, extends downwardly through basemember 8 and is provided With a shoulder 56 adjacent its head, thediameter of this shoulder being substantially larger than the diameterof the pin shank 21, and being substantially equal to the diameter ofhole 53 provided in bracket 50. The shank 21 of pin 55 has a diametersubstantially equalling the width of slot 52 formed in the bracket.

The bracket 50 is further provided on each side with spring biasingmembers 51 secured thereon, which members are provided with rollers 58pivotally pinned to the extreme outward front portion of the members,and which, as will be described presently, cooperate with the V-shapedcam surfaces provided on member I6 for biasing operating member I3 toits normal or intermediate position. Each spring member 51 is providedwith a stiffener member 59.

To assemble the circuit controller as a unit on its supporting bracket50, operating member I3 is rst aligned with the opening 5I formed in theforward portion of the bracket, and is then inserted into this opening.When the collar 56 of pin 55, provided for the base member 8, engagesbracket member 50 to prevent further movement of operating member I3into opening 5I of bracket 50, the spring member II may then be actuatedto depress that spring member toward the base member 8, so that theshoulder portion 56 provided on the pin 55 is forced below the bracket50, and the shank 21 of pin 55 is then received by slot 52 provided inthe bracket. The unit may then be actuated in a forward direction, untilthe upturned leg 9 of base member 8 bears against the forward wall ofbracket 5I), and the boss provided for bearing member I2 is received byopening 5I in this bracket. At this position of base member 8, thespring member I I may be released to actuate pin 55 secured thereonupwardly, so that the shoulder portion 56 of pin 55 is contained withinthe hole 53 of the bracket, and the head of the pin bears against theunderside of the bracket, to which position the spring actuation of themember II biases the head. Also in this position of base member 8, therollers 58 porvided on the spring member 51 secured to bracket 50 enterthe notches of the V-shaped cam surfaces moulded on member I6, so thatthe member I3 and member |6 secured thereto, are positioned as shown inthe drawings.

In the normal position of operating member I3, as shown in Figs. l, 2and 3, the cam member IG governing the contacts of stacks SI and S2 isalso in itsnormal or intermediate position. When operating member I3 ispushed inwardly to move cam member IS to its extreme inward position toselectively govern the control contacts as explained hereinbefore, thecam member I5, moving in response to the movement of member i3, actuatesits forward V-shaped cam surfaces into engagement with the rollers 5Stoforce them apart against their spring bias. When the force exerted uponthe operating member I3 to actuate it inwardly is removed, the rollers58 in response to their spring bias return member I6 and operatingmember I3 to their normal positions, so that the control oontactsgoverned thereby are restored to their normal positions. Likewise, whenmember I3 is is pulled outwardly to actuate cam member I5 to its outwardposition wherein the contacts are selectively controlled as explainedhereinbefore, the rollers 58 are forced apart by virtue of the action ofthe rearward surfaces oi the V-shaped cam surfaces formed on member I6so that when the operating member is released, the rollers 58 inresponse to their spring bias return cam member I6 and operating memberI3 to their normal positions, and the contacts controlled by cam I6 alsoare restored to their normal positions.

It should be noted that a circuit controller constructed in accordancewith our invention may be readily attached to or detached from a controlpanel. rIhat is to say, since the circuit controller and indicator areincorporated into a single unit, the bracket 5% may be securely xed tothe control panel, and the controller unit may then be attached to, ordetached from, the bracket by actuating spring member II to therebyactuate the locking pin 55 provided for the unit so that the shank 21 ofpin 55 is received by the slot 52 provided in bracket 5G, and thenactuating the unit to attach or remove the unit, as the case may be.Preferably, as can be seen in Figs. 2 and 3, the pin 55 is disposed at aslight angle with respect to the opening 53 provided in bracket 55, sothat in the event base member 8 oi the controller unit moves rearward(as, for example, in response to the actuation of operating member I3 toits extreme inward position), the shoulder 55 will bite into thesidewalls of opening 53 provided in bracket 55 and the pin 55 will notbeforced downward to a position wherein its shoulder clears the bracket5i). Since the pin`55 will not be moved downward under the aboveconditions,

the engagement of shoulder 56 with bracket 53 retains the controllerunit secured to its 4associated supporting bracket.

As shown, a spring clip 55a may also be provided for pin 55 and may beproportioned so that when fastened or clipped to the pin 55, the clipwill prevent the movement of pin 55 to its full down position whereinits collar 55 clears the bracket 59, with the result that the controllerunit may be removed from its associated supporting bracket only afterthe clip 55a. has l been removed from engagement with locking pin 55. Itshould be pointed out that, with the pin 55 having its shoulder 55proportioned to be engaged by the sidewalls of hole 53 of bracket in themanner previously described, the clip 'f 550; need not necessarily beused to maintain the controller unit secured to its supporting bracket.However, the clip a may be employed as shown to further insure thatunder all conditions the controller unit can be removed from itssupporting bracket only after the clip is removed from its pin 55 tothereby permit the actuation of the pin to its full down positionwherein shoulder 55 clears the supporting bracket 50.

One advantage of constructing a circuit controller in accordance withour invention, is that such construction enables a controller unit to bedetachably secured to a control panel. This feature is particularlyadvantageous inasmuch as rapid interchange of circuit controllers canthen be effected, whereby one controller unit may be removed from thepanel and another unit placed in its bracket to function with thecontrol apparatus of the system, while the removed unit is beinginspected or repaired.

Another advantage of a circuit controller constructed in accordance withour invention is the provision of a moulded insulating cam member whichcombines in a single unit the multiple functions of controlling theoperation of the contact members, of controlling the operation of thebiasing means, and of providing individual compartments or recesses foreach of the indication lamps and wherein each lamp is positioned.

This construction permits a three-position circuit controller to becombined with a duplex light indicator in a unitary controller structurehaving the least possible external dimensions, and requiring no morepanel space than is usually required for a three-position circuitcontroller of the ordinary construction.

In addition, the specific construction of the biasing means provided forthe circuit controller is such that the lateral forces exerted upon theoperating member IS, resulting from the biased engagement of the rollers53 with the V-shaped cam surfaces formed on the member IE, oppose andbalance each other so that the operating member I3 is maintained inaxial alignment with its bearing I2, and is free to operate within itsbearing without any tendency of the member to bind due to an unbalancedforce being exerted thereon.

Referring now to Figs, 5 and 6, a second form of circuit controllerembodying our invention as shown comprises a supporting bracket 60having an upturned leg at either end, the forward leg 5I being providedwith an opening 62 threaded to receive a bearing member 53, and therearward leg 54 being provided with an opening 65 in axial alignmentwith forward opening 62. An operating member is mounted in bearing 63and in opening 65 for longitudinal sliding movement between twopositions. The operating member comprises a cylindrically formed rod 66having its rearward end slidably mounted in opening b5 of rear bracketleg G4, and provided on its forward end (see Fig. 5) with a threadedstud engaged by an internally threaded opening provided in a sleevemember 6l. The parts are so proportioned that with bearing 63 threadedinto opening 62 of bracket leg 6I, and with rod 65 having its one endmounted in opening 65 of leg 64, the sleeve 61 when threaded onto rod 66is mounted in bearing G3, so that the operating member formed by thecooperation of sleeve 61 with rod 8G is mounted for longitudinal slidingmovement.

The operating member normally occupies its normal position as shown inFigs. 5 and 6, and is adapted at times to be pushed inwardly from itsnormal position to one extreme position and at other times to be pulledoutwardly from its normal position to another extreme position.

The movement of the operating member in each longitudinal direction islimited by shoulders formed on rod 66, the shoulders being so arrangedas to permit a predetermined movement in either direction before theshoulders engage the rear face of bearing 63 or the rear leg of bracket60, as the case may be. The movement of the operating member between itstwo extreme positions is adapted to selectively operate control contactsprovided for the circuit controller, in a manner to be explained indetail presently. As shown, sleeve 61 is provided with an integralbutton adapted to be grasped so that the operating member may be readilyoperated between its two extreme positions.

'I'he operation of the control contacts is governed by a single mouldedcam member 68 formed of insulating material. Cam 68 is sccured to rod66, preferably by being moulded thereon, and is provided on eitherlateral side with a V-shaped notch. The cam 68 is further provided onits upper side with an inverted V- shaped cam. 'Ihe function of theV-shaped notches and cam provided on cam member 68 will be pointed outpresently.

An insulating member 69 is secured to the rearward leg 64 of the bracket60 by means of screws 10. Clamped between the member 69 and bracket leg64 are a pair of spring biasing members 1|, one for each side of themoulded member 68, and which spring members are provided on their outersprung ends with pivotally arranged rollers 12. The rollers 12 arebiased by virtue of their attached spring members 1i into the notches ofthe V-shaped cam surfaces formed on either lateral side of the member68, and thus serve to bias member 68 to a normal position intermediateits two extreme positions.

The member 69 supports control contacts provided for the circuitcontroller in two groups or stacks S3 and S4. Stack S3 is shown in Fig.6 and comprises a plurality of superposed insulating blocks 13a, 13b,13e, and 13d, which are secured to member 69 by insulated screws 14. Amovable contact finger 15 is clamped between block 13a and member 69together with a metallic stop 16 adapted to prevent downward movement ofthe finger, and is provided at its outer end with a bend 11 adapted tobe engaged by the rearward cam surface of the inverted V-shaped camformed on member 68. 'Ihe bend 11 of this contact nger 15 is alsoprovided with an upwardly projecting insulating block 18. A fixedcontact finger 19 is clamped between blocks 13a, and 13b together with afixed metallic stop 8l, and a second fixed contact finger 80 is clampedbetween blocks 13e and 13d together with another xed metallic stop v8l.A second movable contact finger 83 is clamped between the blocks 13b and13C, and is provided with an integral extension engageable by theinsulated block 18 carried by the bend 11 formed in the outer end of therst movable contact finger 15. Normally,

the contacts of stack S3 are in the position illus- 'trated in Fig. 6,wherein contact fingers 15 and 83 are out of engagement with contactfingers 19 and 88, respectively. When operating member :66 is actuatedto move cam member 68 formed thereon to its inward position, therearward cam `surface of cam 68 engages the bend 11 formed `on contactflnger 15 to actuate that finger upwardly and into engagement withcontact fin- ;ger 19, and the insulated block 18 carried by contact nger15 actuates contact finger 83 upward- 1y into engagement with contactfinger 80. Also in this inward position of cam member 68, the rollers 12are forced apart by the forward cam surfaces of the V-shaped notchesformed in the lateral sides of member 68, so that the rollers exertlateral forces upon the cam surfaces sufficient, when the forceactuating operating member 66 inwardly is removed, to return cam member68 and operating member 66 to their nor-V mal positions, wherein therollers 12 engage the notches of the V-shaped cam surfaces.

Contact stack S4 is shown in Fig; 7 and com^ prises a plurality ofsuperposed insulating blocks 84a, 84h and 84e secured to member 69 bymeans of the insulated screws 14. A movable contact finger is clampedbetween blocks 84ay and 841), and is provided at its outer end with areturn bend 86 adapted to be engaged by the forward cam surface of theinverted V-shaped cam formed on member 68. The contact finger 85normally engages a fixed contact finger 81, which is clamped betweenblock 69 and block 84a, and which is provided with a relatively stiffmetallic stop 88 clamped similarly with its contact finger. A secondfixed contact finger 89, provided with a metallic stop 90, is clampedbetween the blocks 84h and 84e and is adapted to be engaged by contactfinger 85 when return bend 86 of the latter finger is engaged by theforward cam surface of member 68. Thus with cam member 68 in its normalposition, contact linger 85 engages contact finger 81, but whenoperating member 66 is pulled outwardly so that cam member 68 is movedto its outer position, the forward cam surface of member 66 engages thereturn bend 86 formed on contact finger 85 to` force that fingerupwardly out of engagement with Contact finger 81 and into engagementwith contact finger 69. In this position of cam member 68, the rollers12 are engaged by the rearward cam surfaces of the V-shaped notchesformed in the lateral sides of member 68 and are forced apart underspring tension so that when the force actuating operating member 66 isremoved, the rollers act upon the rearward cam surfaces o1` the V-shapednotches to return cam member 68 and Operating mem-ber 66 to their normalpositions wherein rollers 12 engage the notches of the V-shaped surfacesformed on the lateral sides of cam member 68. It is understood, ofcourse, that the contact stock arrangement of stacks S3 and S4 may bevaried to best suit the particular contact engagement required for eachspecific application of the circuit controller.

As indicated in Fig. 6, a circuit controller' constructed in the mannerjust described may readily be mounted upon a control panel. To mount thecontroller on a panel, the panel is provided with an opening adapted toreceive the threaded boss of bearing member 63, and the sleeve 61 isremoved from engagement with rod 66 so that the circuit controller maybe positioned with its forward bracket leg 6I engaging the rear face oi'the panel. The opening 62 of leg 6I then is aligned with the panelopening so that bearing 63 may be threaded through the panel openinginto opening 62 of bracket leg 6 l, whereupon the bearing when tightenedsecures the controller to the panel. The sleeve 61 then may be threadedonto rod 66, thereby forming the operating member of the controller andcompleting its assembly upon the panel.

From the foregoing description, it can be seen that we have provided athree-position circuit controller normally biased to an intermediateposition by means of opposing, balanced lateral only two forms ofcircuit controllers embodyingy our invention, it is understood thatVarious changes and modifications may be made therein within the scopeof the appegided claims without departing from the spirit and scope ofour invention.

Having thus described our invention, what we claim is:

1. In a detachable panel mounted circuit controller, in combination, abracket formed on one end with an upturned leg adapted to be secured vto the rear face of a control panel and having an opening which alignswith an opening in said panel, a base member, means for detachablysecuring said base member to said bracket, an operating member, abearing member secured to said base member in said operating member forlongitudinal sliding movement between two eXtreme positions, saidoperating member projecting through said openings in said panel andbracket to the front face of said panel, contacts secured to said basemember and cooperating with said operating member for selectiveoperation in accordance with the position of said operating member, andmeans secured to said bracket and cooperating with said operating memberfor biasing said operating member to a position intermediate its two eX-treme positions.

2. In a detachable panel mounted circuit controller, in combination, abracket formed on one end with an upturned leg adapted to be secured tothe rear face of a control panel and having an opening which aligns withan opening in said panel, a base member, means for detachably securingsaid base member to said bracket, an operating member, a bearing membersecured to said base member in axial alignment with said openings insaid panel and bracket for mounting said operating member forlongitudinal sliding movement between two eXtreme positions, saidoperating member projecting through said openings in said panel andbracket to the front face of said panel, a moulded insulating cam membersecured to said operating member and provided with operating camsurfaces and with biasing cam surfaces, contacts secured to said basemember and cooperating with the operating cam surfaces of said cam forselective operation in accordance with the position of said operatingmember, and spring biasing members secured to said bracket andcooperating with the biasing cam surfaces of said cam for biasing saidoperating member to a position intermediate its two extreme positions.

3. In a detachable panel mounted circuit controller, in combination, abracket formed on one end with an upturned leg adapted to be secured tothe rear face of a control panel and having an opening which aligns withan opening in said panel, a base member secured to said bracket, anoperating member, a bearing member secured to axial alignment with saidopenings in said panel and bracket for mounting said base member inaxial alignment with said openings in said panel and bracket formounting said operating member for longitudinal sliding movement betweentwo extreme positions, said operating member projecting through saidopenings in said panel and bracket to the front face of said panel, amoulded insulating cam member secured to said operating member andprovided on each lateral side with V-shaped biasing cam surfaces, saidcam member also being provided with operating cam surfaces, contactssecured to said base member and cooperating with the operating camsurfaces of said cam for selective operation in accordance with theposition of said operating member, and spring biasing members secured tosaid bracket one for each lateral side of said cam member andcooperating with the V-shaped biasing cam surfaces of said cam forbiasing said operating member to a position intermediate its two extremepositions.

4. In a detachable panel mounted circuit controller, in combination, abracket formed on one end with an upturned leg adapted to be secured tothe rear face of a control panel and having an opening which aligns withan opening in said panel, a base member secured to said bracket, anoperating member, a bearing member secured to said base member in axialalignment with said openings in said panel and bracket for mounting saidoperating member for longitudinal sliding movement. between two extremepositions, said operating member projecting through said openings insaid panel and bracket to the front face of said panel, a mouldedinsulating cam member secured to said operating member and provided oneach lateral side with V-shaped biasing cam surfaces, said cam memberalso being provided with operating cam surfaces, contacts secured tosaid base member and cooperating with the operating cam surfaces of saidcam for selective operation in accordance with the position of saidoperating member, and spring biasing members secured to said bracket onefor each lateral side of said cam member, said spring biasing membersbeing so disposed with relation to the V- shaped ,cam surfaces of saidcam as to bias said operating member to a position intermediate its twoextreme positions by virtue of equal opposing forces which maintain saidoperating member in alignment with said bearing member.

5. In a push-pull circuit controller of the class wherein a base memberdetachably secured to a bracket member supports a set of contacts andalso mounts for longitudinal sliding movement between two extremepositions an operating member which selectively operates said set ofcontacts, the combination with said operating member and with saidbracket of a cam member secured to said operating member and havingoppositively disposed V-shaped cam surfaces, and spring biasing memberssecured to said bracket and disposed one to engage each of said V-shapedbiasing cam surfaces in such manner that said operating member is biasedto a position intermediate its two extreme positions by opposed andbalanced biasing forces.

HERBERT L. BONE. wrLLIAM E. SMITH. ROBERT A. woons.

